This Phase I clinical trial intends to establish the maximum tolerated dose and dose limiting toxicity of low dose continuous infusion topotecan in combination with Doxil for advanced malignancies and establish a recommended Phase II dose based on the MTD. Pharmacokinetic and pharmacodynamic studies of topotecan will be secondary endpoints. Anti-tumor activity will also be assessed. In 1999, the oral form of topotecan was used instead of the injectable.